Always do pre-string inspection

Discussion in 'Badminton Stringing Techniques & Tools' started by kwun, Jan 21, 2020.

  1. kwun

    kwun Administrator

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    Found this while inspecting a new client's racket. Definitely will not survive the stringing. Saved quite a bit of time and stress just spending 15 seconds to look over the frame.

    BTW, what's LiNing thinking? This design has such a huge weakness, and honestly I don't see any benefit to this design whatsoever other than looking cute.

    [​IMG][​IMG]
    [​IMG]
     
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  2. Antxn

    Antxn Regular Member

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    Wow! Looks quite deep...

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  3. stradrider

    stradrider Regular Member

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    Lucky you cought it before starting! Can you elaborate about design weakness? What do you mean? Just thin or something else?
     
  4. Sumanth99

    Sumanth99 Regular Member

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    It will be good if people who bought an Aeronaut and faced/not faced similar problems can discuss their experience.
     
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  5. kwun

    kwun Administrator

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    Looking at the 2nd photo. the 5/7 o'clock area of the frame has a slit/gap in it. the inner part is thinner, a gap, and then outer part that has 1/2 the material of a normal frame.

    That's just dumb, as the string exits the inner part of the frame at an angle, that creates a compression forces (>20lbs for each string) that presses the thin strip inwards. There is no way for it to survive long term. Once the inner piece breaks, the outer piece (which only have 1/2 the material) ultimately buckles also which is exactly what happens here.
     
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  6. stradrider

    stradrider Regular Member

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    Ah, thanks for the explanation, thought it was just color paint in the photo... It's completely idiotic, agreed!!!
     
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  7. Rimano

    Rimano Regular Member

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    I think this is a good point. This racket design has been around for a while now and if it was really a big problem, we should've seen more breakages.

    My 7000Bs are holding up fine. But I only strung around 26lbs. One of them didn't even warp when a string broke in a racket bag. However I haven't played with them long enough to say they good or bad in terms weakness.


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  8. s_mair

    s_mair Regular Member

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    Those Airstream slits are their big "let's make box frames more aerodynamic!"-marketing gag for the Aeronaut series and have been introduced quite a while ago (was it the N50III or the N55III that had it first)? So there has to be hundreds of thousands of rackets being sold carrying those slits and afair, this is the first report on BC regarding a broken frame in that area. My gut feeling: This isn't such a significant design flaw after all or there would have been more complaints coming up (we don't have to discuss that the effect on aerodynamics is slim to none though...).

    But anyways, it's a good reminder to take the pre-stringing inspection seriously! Waste of time and strings and let's not forget the inevitable and uncomfortable discussions with the racket owner when the racket really dies on your machine. :rolleyes:
     
    #8 s_mair, Jan 21, 2020
    Last edited: Jan 22, 2020
  9. Ouchie

    Ouchie Regular Member

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    Because...military grade carbon fibre.
    Better than paramilitary and civilian grade carbon fibre.
     
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  10. ucantseeme

    ucantseeme Regular Member

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    I don't see here a weak built on Li-Ning rackets. I have seen such cracks on a few clients racket which I didn't strung. It's a common crack pattern without chips which is result when you hit the floor or a steel rope which holds the net. These cracks always run through holes (less material in this spot) and are a result when the head deforms too much. I have a Victor and a Yonex (clients) here which have a similar crack and both happend due hitting on the net with force out of anger and one kissed the floor on a late lift from the floor. The Victor kissed the floor and had at the same spot the crack and it don't have any slits. So IMO clearly nothing which happen Li-Ning exclusive. Can also happen when the client don't cut the broken string complete or uneven.
     
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  11. Rimano

    Rimano Regular Member

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    Yeah. I had a N50iii and didn't think too much of the technology back then. It swung and felt similar to a bravesword 12, so I didn't see the point of it.

    However for the 7000B, it's feels a lot better. It's either they tweaked the technology slightly or my tastes have changed.

    Note the aeronaut on the 4000B has 2 slits, one either side of the T joint. The 7000B has 2 either side, 4 in total. So the aeronaut technology can be different between rackets.



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  12. ucantseeme

    ucantseeme Regular Member

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    Anybody covered on identical rackets the slits with electric tape to notice a difference in aerodynamics?
     
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  13. aqua26

    aqua26 Regular Member

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    Is there any Crack in the lower frame as well or just in the thinner One.
    It is very difficult to understand why there is a crack in the inner frame ??
     
  14. kwun

    kwun Administrator

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    yup. there is a crack in the thin inner frame as well as the thicker frame, one grommet apart.
     
  15. kwun

    kwun Administrator

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    the slit is so small, most of the air will be caught in the high friction boundary flow with the frame surface. my guess is the difference is minimal.

    Best is still the bravesword style, fix the outer flow is much more effective.
     

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